For a heating element for a heated seat of a vehicle, metallic heating elements, such as nichrome wire, iron wire, nickel wire, silver-plated copper wire, have been typically used. Since these metallic heating elements have substantially low specific resistance, there is risk of fire when an over-current flows in the metallic heating elements. Furthermore, since the metallic heating elements are usually configured with series of connected coils, electrical disconnection may occur.
As an alternative according to such problems, a plate heating element in which carbon fiber is used as a resistance heating element and the resistance heating elements are connected in parallel may be used. The plate heating element using carbon fiber may be obtained by weaving strands of carbon fiber into a radial pattern and connecting various forms of electrodes arranged in parallel to each end of the pattern using a fixing thread. When electric power is applied to the electrodes, the carbon fiber generates heat.
The carbon fiber plate heating element has the advantages, for example, low power consumption, a thermal comfort through surface heating, and high heating rate compared to a linear metallic wire heating element. However, the heating element for a heated seat may be expensive, and the lifetime of the heating element may depend on durability of the electrodes arranged at each end of a carbon fiber-woven mat and the adhesive stability of the electrodes. Although some conventional electrodes have configured to improve the durability, improvement in durability of the electrodes in conventional arts may be limited to a pattern in arrangement of the electrodes.
Therefore, the present invention may include changing the shape and structure of an electrode used for a carbon fiber plate heating element, to reduce a defect rate of the electrode during manufacturing processes and to improve physical durability of the electrode, thereby leading to an improved quality of products.
In a conventional art, a plate heating seat and a method for manufacturing the same have been developed. For example, a first power line of a lace shape and a second power line of a linear shape are attached in parallel to each end of a main seat, and multiple rows of carbon fiber are woven into a variety of patterns using a loom or knitting machine and attached to the main seat. Meanwhile, such conventional art may cause a misalignment when the power lines of the carbon fiber heating element are fixed to predetermined portions of the main seat and materials may be wasted when the woven power lines are cut into desired sizes whenever they are used.
In some related arts, a method may include a process of bonding electric wires on a main seat using a hot-melt adhesive, and thus an additional cost may incur. Further, in other cases, electric wires may be linearly arranged; therefore, seats and heating elements may not be flexible in design. In another example of the conventional methods, electrodes constituting the electric wire may be linearly arranged; therefore the electrodes may be deteriorated in tensile strength and durability due to repeated seating by a user.
The foregoing is intended merely to aid in the understanding of the background of the present invention, and is not intended to mean that the present invention falls within the purview of the related art that is already known to those skilled in the art.